1. Technical Field
The present invention relates to a system for providing directory assistance services to telephone users in a telephone network and, in particular, maintaining a connection to a directory assistance platform and providing for automatic reconnection to a directory assistance provider.
2. Discussion of the Related Art
Telephone calls from one party to another are made through telephone networks, with telephone switches and private branch exchanges (xe2x80x9cPBXxe2x80x9d) employed as necessary in order to connect networks and customers. Customers frequently make use of directory assistance systems to reach their desired parties. When using a directory assistance system (sometimes referred to as a xe2x80x9cdirectory assistance platformxe2x80x9d), a caller first dials the appropriate telephone number or access code. Telephone users usually access a directory assistance system through a carrier switching center. Once connected to a directory assistance provider, such as a live operator or a voice server, the caller identifies the party whose telephone number is desired. The correct number is located and may be reported to (by voice or computer-generated speech), and/or dialed for, the caller. It is increasingly common for directory assistance systems to connect the caller to the caller""s desired number in addition to, or in place of, simply providing the number to the caller. This is particularly helpful to callers using cellular or other forms of wireless telephones, who may be engaged in other activities at the same time and therefore unable to take note of the number as it is recited. Typically, once the caller has been given the number and/or the number is dialed for the caller, the caller""s connection through the directory assistance platform is terminated.
Termination of the connection through the directory assistance platform has a number of disadvantages. For example, if the caller is given or connected to an incorrect telephone number, the caller must contact the directory assistance system again or inquire elsewhere to obtain the correct number. This naturally requires additional action and expense on the caller""s part. Moreover, reconnection to the directory assistance platform requires reallocation of directory assistance resources to the customer call. In view of the previous connection through the directory assistance platform, reconnection and reallocation is unnecessary, time consuming, and under some circumstances, wasteful. Similarly, even if the telephone number to which the caller is connected is correct, the line may be busy, there may be no answer, the destination party is telephone network may be inoperable, etc. In such circumstances, the caller often will want to contact a different party, again requiring the aid of the directory assistance system. Requiring separate and repeated connections to a directory assistance platform incurs added monetary expense on the caller""s part, because directory assistance platforms typically charge a fee for each separate connection. Conversely, if a caller""s connection is maintained to the directory assistance platform, multiple actions may be taken to assist the caller without necessarily incurring such additional fees.
It is known in the art to provide proactive call services to calling and/or called parties. As demonstrated in U.S. Pat. No. 5,414,754, proactive call services allow parties to, for example, establish a conference call to a third party, leave recorded messages for an unavailable called party, or instruct a telephone service provider to repeatedly attempt to connect to an unavailable party for a pre-determined period of time after an unsuccessful call attempt. Most proactive call services are provided only when a call has been successfully established between two (or more) parties. For such call services, one of the parties requests the service by entering a specified access code. Other proactive call services are available only when a call is unsuccessful (e.g., the caller encounters a busy signal or a ring-no-answer condition); to access these services, the caller is prompted to select one from a menu. Both methods suffer the disadvantage of requiring affirmative action by one or more parties in order to access the services.
Prior art directory assistance systems suffer from a further disadvantage in that they typically lack dedicated resources for monitoring telephone connections to calling or called parties. For example, in U.S. Patent No. 5,414,754, one tone detecting device monitors up to 1,344 connections by using a multiplexer. The period of time for which each connection is monitored is critical to this method of operation. To service so many connections on an equal time-sharing basis, the device cannot monitor one particular connection for more than a very short period of time (illustratively, on the order of milliseconds) before switching to and monitoring others. If the time period is too short, this method has the deleterious effect of requiring a party to press a key for an extended period of timexe2x80x94long enough to ensure that the monitoring digital signal processor (xe2x80x9cDSPxe2x80x9d), perhaps a dual-tone multi-frequency (xe2x80x9cDTMFxe2x80x9d) receiver, cycles back to the party""s connection in time to detect the keypressxe2x80x94or risk the possibility that the DSP will miss the party""s keypress. Another disadvantage to this method is that normal voice energy, or transient signals such as from interference or crosstalk, may cause a DSP that is monitoring the connection to mistakenly report that a party pressed a key. This disadvantage is even more pronounced in a wireless environment, where the bit error rate or degraded audio quality of the connection often precludes the receipt of a continuous tone.
Another disadvantage in prior directory assistance systems is the inability to restrict the caller""s use of the directory assistance system to connect to specified parties. For example, the party paying for a caller""s wireless telephone service may wish to restrict the caller from making any long-distance calls, or to limit the caller to calls to other parties within one organization, etc. Without the ability to limit the caller""s connections through the directory assistance system, the caller could circumvent the paying party""s restrictions by having the directory assistance system complete the call for him or her.
Accordingly, there is a need in the art to provide a method and apparatus by which a caller can, for the duration of a telephone call (i.e., until the calling telephone disconnects from the directory assistance platform), maintain his or her connection to the directory assistance platform and repeatedly receive directory assistance in a variety of forms with minimal or no action on his or her part. There is also a need in the art for means and an apparatus for allocating a monitoring resource, such as a DSP, to a minimal number of telephonic connections. In addition, there is a need for means and an apparatus for verifying a caller""s authorization to connect to a requested destination party through a directory assistance platform.
In view of the above disadvantages of the related art, it is an object of the present invention to provide a method and apparatus for maintaining a telephonic connection for the duration of a telephone call through a directory assistance platform (i.e., until the calling telephone disconnects from the platform) and automatically reconnecting a directory assistance-routed caller to a directory assistance provider.
It is a further object of the present invention to detect, during a call to a customer""s destination party, a telephone network communication problem that causes the call to be unsuccessful, and to connect the caller, with substantially no further action on his or her part, to a live operator for further assistance.
It is another object of the invention to detect a ring-no-answer condition while attempting a call to a customer""s destination party, and, upon such detection, to maintain the connection attempt and present the caller with a menu of directory assistance service options, including the option to continue monitoring the ring tone.
It is a further object of the invention to detect a busy signal while attempting a call to a customer""s destination party, and, upon such detection, to terminate the connection attempt and present the caller with a menu of directory assistance service options, including the option to re-dial the same number.
It is also an object of the invention to provide a method and apparatus for providing directory assistance services, such as connecting customers to directory assistance providers, allowing repeated directory assistance requests from each customer, searching for information to satisfy directory assistance requests, providing such information to customers, and connecting customers to their desired destination parties, as well as enhanced directory assistance services, e.g., recording messages from customers for delivery to destination parties and allowing destination parties, upon delivery of a recorded message, to return the customer""s call with minimal action by the destination party.
It is a further object of the invention to verify a customer""s authorization to complete calls through a directory assistance system. To enable such verification, along with the customer""s call, data concerning the calling telephone number and the location from which the call originated is also received. Based upon the caller""s identity and stored information concerning restrictions on the customer""s calling authority, the caller""s authorization for connecting to desired destination parties can then be verified.
It is a still further object of the invention to provide a directory assistance customer with numerous opportunities to request, with minimal action on the customer""s part, the directory assistance system to report the desired destination telephone number.
It is also an object of the invention to provide a directory assistance customer with the customer""s destination telephone number via the customer""s alphanumeric pager.
It is a still further object of the invention to implement the above objects for callers using wireless telephones.
In accordance with the present invention, a directory assistance system is provided that includes a telephone switch or PBX for receiving, establishing, routing, and connecting telephone calls, plus telephone operators, communication links to physically connect the directory assistance system components, and one or more computers, including at least one voice server, to perform a variety of directory assistance functions (e.g., maintain and search databases containing telephone numbers, billing information, call information, etc.; store and execute instructions relating to the operation of the switch or PBX; provide automated voice services and operator functions). Providing access to and from the telephone switch are external communication links that support standard T1, Common Channel Signalling System 7 (xe2x80x9cCCSS7xe2x80x9d), or Integrated Digital Services Network (xe2x80x9cISDNxe2x80x9d) communications.
Calls into the directory assistance system and connections from the system to a caller""s destination number are made over external communication links. Telephone connections over the communication links are monitored to detect keypresses and connection status conditions (e.g., busy signal, dial tone). For example, outbound connections to destination parties are monitored by call progress analyzers (xe2x80x9cCPAxe2x80x9d) to determine if an attempted call is unsuccessful (e.g., a busy signal is detected); once applied, CPAs are allocated to the outbound connection for a period of time sufficient in length (illustratively determined by a specified number of rings of the destination telephone) to determine the success or failure of the connection attempt.
The directory assistance system does not drop its connection to, and involvement in, a calling party""s connection as soon as it initiates a new call leg (i.e., an outbound call to a destination telephone). Rather, the directory assistance system maintains contact, ready to provide further assistance from a directory assistance operator or a voice server until the calling party disconnects from the directory assistance platform. By remaining in the call flow, a directory assistance system according to this invention is able to provide much faster response to customers"" subsequent assistance needs than was heretofore available, which is of particular value to wireless customers who may be distracted by other events. In previous directory assistance systems, in which the system would terminate its involvement after the customer was given its desired telephone number or the directory assistance provider initiated a call attempt to the desired party, the customer was required to reconnect to the directory assistance system if additional assistance was desired.
In a directory assistance system according to the present invention, incoming directory assistance request calls are received by a telephone switch, which is controlled by a switch host computer, via an inbound member of the external communication links and routed to a directory assistance provider. The directory assistance provider may be either a live operator or a voice server that provides automated directory assistance. The switch host computer stores and updates information concerning the status of each active directory assistance call. In addition, a call record is created on a system server to store, for billing purposes, the history of the customer""s call. After receiving a request from the caller, the directory assistance provider locates and retrieves the telephone number of the caller""s desired destination party by searching directory assistance information stored on system servers. An outbound member of the communication links is seized in order to connect the caller to his or her party, and the destination telephone number is dialed over that outbound member. A dual-tone multi-frequency (xe2x80x9cDTMFxe2x80x9d) receiver is applied to the inbound member to detect customer keypresses, which may represent pre-specified directory assistance requests. A call progress analyzer (xe2x80x9cCPAxe2x80x9d) is applied to the outbound member for a period of time to monitor the member for any one of several pre-determined telephone call connection status conditions that indicate an unsuccessful call attempt. Upon detection of such a connection status condition, or when the called party disconnects, the caller is redirected to a directory assistance provider for further assistance.